Grant-free uplink transmissions

ABSTRACT

A wireless transmit receive unit (WTRU) may send a grant free transmission comprising a first and a second part, each of which may be associated with a priority. The first part&#39;s priority may be higher than the second part&#39;s priority. The WTRU may select a first back of value from a first range of back off values. The WTRU may determine whether the grant free transmission was successful. If the grant free transmission was not successful, the WTRU may send a retransmission of the grant free transmission, which may include the first part and may not include the second part. The retransmission may select a second back off value from a second range of back off values, which may be a larger than the first range of back off values. The second back off value may indicate the number of grant free resource to skip prior to sending the retransmission.

CROSS REFERENCE

This application is the National Stage Entry under 35 U.S.C. § 371 ofPatent Cooperation Treaty Application No. PCT/US2018/061228, filed Nov.15, 2018, which claims priority from U.S. Provisional Patent ApplicationNo. 62/586,473, filed Nov. 15, 2017, the contents of all of which is arehereby incorporated by reference herein in their entireties itsentirety.

BACKGROUND

In wireless communication systems, a central node may serve one or morewireless transmit/receive units (WTRUs). When a central node serves oneor more WTRUs, the opportunity to send transport blocks (TB) to thecentral node may be administered by the central node. For example, thecentral node may schedule a WTRU uplink (UL) transmission.

SUMMARY

A wireless transmit receive unit (WTRU) may be configured to send grantfree transmissions on grant free resources. The WTRU may send a firstgrant free transmission that comprises a first part and a second part.The first part and the second part may each be associated with apriority. The priority associated with the first part may be a higherpriority than the priority associated with the second part. For example,the first part may include acknowledgement information (e.g., hybridautomatic repeat request (HARQ)) and the second part may include channelquality information (CQI). The WTRU may select a first back off valuefor the first grant free transmission from a first range of back offvalues. The WTRU may determine whether the first grant free transmissionwas successful. If the first grant free transmission was not successful,the WTRU may send a retransmission of the first grant free transmission.The retransmission may include the first part and may not include thesecond part. The WTRU may select a second back off value for theretransmission from a second range of back off values. The second rangeof back off values may be a larger range than the first range of backoff values. The second range of back off values may indicate the numberof grant free resource to skip prior to sending the retransmission.

Multiplexing may be used on the first grant free transmission and/or theretransmission of the first grant free transmission. The first grantfree transmission may be multiplexed on a transport block using a firstredundancy version. The retransmission may be multiplexed on anothertransport block using a second redundancy version. The second redundancyversion may be associated with a higher redundancy than the firstredundancy version.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of examples in conjunction with the accompanying drawingswherein:

FIG. 1A is a system diagram illustrating an example communicationssystem in which one or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram illustrating an example wirelesstransmit/receive unit (WTRU) that may be used within the communicationssystem illustrated in FIG. 1A according to an embodiment;

FIG. 1C is a system diagram illustrating an example radio access network(RAN) and an example core network (CN) that may be used within thecommunications system illustrated in FIG. 1A according to an embodiment;

FIG. 1D is a system diagram illustrating a further example RAN and afurther example CN that may be used within the communications systemillustrated in FIG. 1A according to an embodiment;

FIG. 2 shows an example of scheduled grant-free (GF) resources duringslots;

FIG. 3 shows an example grant-free resource scheduled within a slot(e.g., scheduled within a slot by a gNodeB (gNB));

FIG. 4 shows an example grant-free resource scheduled within a slot(e.g., scheduled within a slot by a gNB) and three wirelesstransmit-receive unit (WTRU) attempts to use the resource for the WTRU'spending transport block (TB);

FIG. 5 shows an example grant-free resource scheduled within a slot(e.g., scheduled within a slot by a gNB) and three WTRU attempts to usethe resource for the WTRU's pending TB.

DETAILED DESCRIPTION

A detailed description, which may include illustrative embodiments, willnow be described with reference to the various Figures. Although thisdetailed description may provide detailed examples of possibleimplementations, it should be noted that the details are intended to beexemplary and in no way limit the scope of the application.

FIG. 1A is a diagram illustrating an example communications system 100in which one or more disclosed embodiments may be implemented. Thecommunications system 100 may be a multiple access system that providescontent, such as voice, data, video, messaging, broadcast, etc., tomultiple wireless users. The communications system 100 may enablemultiple wireless users to access such content through the sharing ofsystem resources, including wireless bandwidth. For example, thecommunications systems 100 may employ one or more channel accessmethods, such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tailunique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM(UW-OFDM), resource block-filtered OFDM, filter bank multicarrier(FBMC), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a RAN104/113, a CN 106/115, a public switched telephone network (PSTN) 108,the Internet 110, and other networks 112, though it will be appreciatedthat the disclosed embodiments contemplate any number of WTRUs, basestations, networks, and/or network elements. Each of the WTRUs 102 a,102 b, 102 c, 102 d may be any type of device configured to operateand/or communicate in a wireless environment. By way of example, theWTRUs 102 a, 102 b, 102 c, 102 d, any of which may be referred to as a“station” and/or a “STA”, may be configured to transmit and/or receivewireless signals and may include a user equipment (UE), a mobilestation, a fixed or mobile subscriber unit, a subscription-based unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watchor other wearable, a head-mounted display (HMD), a vehicle, a drone, amedical device and applications (e.g., remote surgery), an industrialdevice and applications (e.g., a robot and/or other wireless devicesoperating in an industrial and/or an automated processing chaincontexts), a consumer electronics device, a device operating oncommercial and/or industrial wireless networks, and the like. Any of theWTRUs 102 a, 102 b, 102 c and 102 d may be interchangeably referred toas a UE.

The communications systems 100 may also include a base station 114 aand/or a base station 114 b. Each of the base stations 114 a, 114 b maybe any type of device configured to wirelessly interface with at leastone of the WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to oneor more communication networks, such as the CN 106/115, the Internet110, and/or the other networks 112. By way of example, the base stations114 a, 114 b may be a base transceiver station (BTS), a Node-B, an eNodeB, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller,an access point (AP), a wireless router, and the like. While the basestations 114 a, 114 b are each depicted as a single element, it will beappreciated that the base stations 114 a, 114 b may include any numberof interconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 104/113, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals on one or morecarrier frequencies, which may be referred to as a cell (not shown).These frequencies may be in licensed spectrum, unlicensed spectrum, or acombination of licensed and unlicensed spectrum. A cell may providecoverage for a wireless service to a specific geographical area that maybe relatively fixed or that may change over time. The cell may furtherbe divided into cell sectors. For example, the cell associated with thebase station 114 a may be divided into three sectors. Thus, in oneembodiment, the base station 114 a may include three transceivers, i.e.,one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and mayutilize multiple transceivers for each sector of the cell. For example,beamforming may be used to transmit and/or receive signals in desiredspatial directions.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet(UV), visible light, etc.). The air interface 116 may be establishedusing any suitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104/113 and the WTRUs 102 a,102 b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 115/116/117 using wideband CDMA (WCDMA).WCDMA may include communication protocols such as High-Speed PacketAccess (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-SpeedDownlink (DL) Packet Access (HSDPA) and/or High-Speed UL Packet Access(HSUPA).

The base station 114 a and the WTRUs 102 a, 102 b, 102 c may implement aradio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA),which may establish the air interface 116 using Long Term Evolution(LTE) and/or LTE-Advanced (LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as NR Radio Access, which mayestablish the air interface 116 using New Radio (NR).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement multiple radio access technologies. For example, thebase station 114 a and the WTRUs 102 a, 102 b, 102 c may implement LTEradio access and NR radio access together, for instance using dualconnectivity (DC) principles. Thus, the air interface utilized by WTRUs102 a, 102 b, 102 c may be characterized by multiple types of radioaccess technologies and/or transmissions sent to/from multiple types ofbase stations (e.g., a eNB and a gNB).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.11 (i.e.,Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperabilityfor Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO,Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), InterimStandard 856 (IS-856), Global System for Mobile communications (GSM),Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and thelike.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, an industrialfacility, an air corridor (e.g., for use by drones), a roadway, and thelike. In one embodiment, the base station 114 b and the WTRUs 102 c, 102d may implement a radio technology such as IEEE 802.11 to establish awireless local area network (WLAN). In an embodiment, the base station114 b and the WTRUs 102 c, 102 d may implement a radio technology suchas IEEE 802.15 to establish a wireless personal area network (WPAN). Inyet another embodiment, the base station 114 b and the WTRUs 102 c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. Asshown in FIG. 1A, the base station 114 b may have a direct connection tothe Internet 110. Thus, the base station 114 b may not be required toaccess the Internet 110 via the CN 106/115.

The RAN 104/113 may be in communication with the CN 106/115, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. The data may have varying qualityof service (QoS) requirements, such as differing throughputrequirements, latency requirements, error tolerance requirements,reliability requirements, data throughput requirements, mobilityrequirements, and the like. The CN 106/115 may provide call control,billing services, mobile location-based services, pre-paid calling,Internet connectivity, video distribution, etc., and/or performhigh-level security functions, such as user authentication. Although notshown in FIG. 1A, it will be appreciated that the RAN 104/113 and/or theCN 106/115 may be in direct or indirect communication with other RANsthat employ the same RAT as the RAN 104/113 or a different RAT. Forexample, in addition to being connected to the RAN 104/113, which may beutilizing a NR radio technology, the CN 106/115 may also be incommunication with another RAN (not shown) employing a GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

The CN 106/115 may also serve as a gateway for the WTRUs 102 a, 102 b,102 c, 102 d to access the PSTN 108, the Internet 110, and/or the othernetworks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) and/orthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired and/or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another CN connected to one or more RANs, whichmay employ the same RAT as the RAN 104/113 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities (e.g., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks). For example, the WTRU 102 c shown in FIG. 1A may be configuredto communicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram illustrating an example WTRU 102. As shownin FIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120,a transmit/receive element 122, a speaker/microphone 124, a keypad 126,a display/touchpad 128, non-removable memory 130, removable memory 132,a power source 134, a global positioning system (GPS) chipset 136,and/or other peripherals 138, among others. It will be appreciated thatthe WTRU 102 may include any sub-combination of the foregoing elementswhile remaining consistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In an embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and/or receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

Although the transmit/receive element 122 is depicted in FIG. 1B as asingle element, the WTRU 102 may include any number of transmit/receiveelements 122. More specifically, the WTRU 102 may employ M IMOtechnology. Thus, in one embodiment, the WTRU 102 may include two ormore transmit/receive elements 122 (e.g., multiple antennas) fortransmitting and receiving wireless signals over the air interface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as NR and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs and/or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, a Virtual Reality and/or Augmented Reality (VR/AR) device, anactivity tracker, and the like. The peripherals 138 may include one ormore sensors, the sensors may be one or more of a gyroscope, anaccelerometer, a hall effect sensor, a magnetometer, an orientationsensor, a proximity sensor, a temperature sensor, a time sensor; ageolocation sensor; an altimeter, a light sensor, a touch sensor, amagnetometer, a barometer, a gesture sensor, a biometric sensor, and/ora humidity sensor.

The WTRU 102 may include a full duplex radio for which transmission andreception of some or all of the signals (e.g., associated withparticular subframes for both the UL (e.g., for transmission) anddownlink (e.g., for reception) may be concurrent and/or simultaneous.The full duplex radio may include an interference management unit toreduce and or substantially eliminate self-interference via eitherhardware (e.g., a choke) or signal processing via a processor (e.g., aseparate processor (not shown) or via processor 118). In an embodiment,the WRTU 102 may include a half-duplex radio for which transmission andreception of some or all of the signals (e.g., associated withparticular subframes for either the UL (e.g., for transmission) or thedownlink (e.g., for reception)).

FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the CN 106.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and/or receive wireless signals from, the WTRU 102a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the UL and/or DL, and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160 b, 160 c may communicate with one another over an X2 interface.

The CN 106 shown in FIG. 1C may include a mobility management entity(MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN)gateway (or PGW) 166. While each of the foregoing elements are depictedas part of the CN 106, it will be appreciated that any of these elementsmay be owned and/or operated by an entity other than the CN operator.

The MME 162 may be connected to each of the eNode-Bs 162 a, 162 b, 162 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM and/or WCDMA.

The SGW 164 may be connected to each of the eNode Bs 160 a, 160 b, 160 cin the RAN 104 via the S1 interface. The SGW 164 may generally route andforward user data packets to/from the WTRUs 102 a, 102 b, 102 c. The SGW164 may perform other functions, such as anchoring user planes duringinter-eNode B handovers, triggering paging when DL data is available forthe WTRUs 102 a, 102 b, 102 c, managing and storing contexts of theWTRUs 102 a, 102 b, 102 c, and the like.

The SGW 164 may be connected to the PGW 166, which may provide the WTRUs102 a, 102 b, 102 c with access to packet-switched networks, such as theInternet 110, to facilitate communications between the WTRUs 102 a, 102b, 102 c and IP-enabled devices.

The CN 106 may facilitate communications with other networks. Forexample, the CN 106 may provide the WTRUs 102 a, 102 b, 102 c withaccess to circuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. For example, the CN 106 may include,or may communicate with, an IP gateway (e.g., an IP multimedia subsystem(IMS) server) that serves as an interface between the CN 106 and thePSTN 108. In addition, the CN 106 may provide the WTRUs 102 a, 102 b,102 c with access to the other networks 112, which may include otherwired and/or wireless networks that are owned and/or operated by otherservice providers.

Although the WTRU is described in FIGS. 1A-1D as a wireless terminal, itis contemplated that in certain representative embodiments that such aterminal may use (e.g., temporarily or permanently) wired communicationinterfaces with the communication network.

In representative embodiments, the other network 112 may be a WLAN.

A WLAN in Infrastructure Basic Service Set (BSS) mode may have an AccessPoint (AP) for the BSS and one or more stations (STAs) associated withthe AP. The AP may have an access or an interface to a DistributionSystem (DS) or another type of wired/wireless network that carriestraffic in to and/or out of the BSS. Traffic to STAs that originatesfrom outside the BSS may arrive through the AP and may be delivered tothe STAs. Traffic originating from STAs to destinations outside the BSSmay be sent to the AP to be delivered to respective destinations.Traffic between STAs within the BSS may be sent through the AP, forexample, where the source STA may send traffic to the AP and the AP maydeliver the traffic to the destination STA. The traffic between STAswithin a BSS may be considered and/or referred to as peer-to-peertraffic. The peer-to-peer traffic may be sent between (e.g., directlybetween) the source and destination STAs with a direct link setup (DLS).In certain representative embodiments, the DLS may use an 802.11e DLS oran 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS)mode may not have an AP, and the STAs (e.g., all of the STAs) within orusing the IBSS may communicate directly with each other. The IBSS modeof communication may sometimes be referred to herein as an “ad-hoc” modeof communication.

When using the 802.11ac infrastructure mode of operation or a similarmode of operations, the AP may transmit a beacon on a fixed channel,such as a primary channel. The primary channel may be a fixed width(e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling.The primary channel may be the operating channel of the BSS and may beused by the STAs to establish a connection with the AP. In certainrepresentative embodiments, Carrier Sense Multiple Access with CollisionAvoidance (CSMA/CA) may be implemented, for example in 802.11 systems.For CSMA/CA, the STAs (e.g., every STA), including the AP, may sense theprimary channel. If the primary channel is sensed/detected and/ordetermined to be busy by a particular STA, the particular STA may backoff. One STA (e.g., only one station) may transmit at any given time ina given BSS.

High Throughput (HT) STAs may use a 40 MHz wide channel forcommunication, for example, via a combination of the primary 20 MHzchannel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHzwide channel.

Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz,and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may beformed by combining contiguous 20 MHz channels. A 160 MHz channel may beformed by combining 8 contiguous 20 MHz channels, or by combining twonon-contiguous 80 MHz channels, which may be referred to as an 80+80configuration. For the 80+80 configuration, the data, after channelencoding, may be passed through a segment parser that may divide thedata into two streams. Inverse Fast Fourier Transform (IFFT) processing,and time domain processing, may be done on each stream separately. Thestreams may be mapped on to the two 80 MHz channels, and the data may betransmitted by a transmitting STA. At the receiver of the receiving STA,the above described operation for the 80+80 configuration may bereversed, and the combined data may be sent to the Medium Access Control(MAC).

Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. Thechannel operating bandwidths, and carriers, are reduced in 802.11af and802.11ah relative to those used in 802.11n, and 802.11ac. 802.11afsupports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space(TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and16 MHz bandwidths using non-TVWS spectrum. According to a representativeembodiment, 802.11ah may support Meter Type Control/Machine-TypeCommunications, such as MTC devices in a macro coverage area. MTCdevices may have certain capabilities, for example, limited capabilitiesincluding support for (e.g., only support for) certain and/or limitedbandwidths. The MTC devices may include a battery with a battery lifeabove a threshold (e.g., to maintain a very long battery life).

WLAN systems, which may support multiple channels, and channelbandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include achannel which may be designated as the primary channel. The primarychannel may have a bandwidth equal to the largest common operatingbandwidth supported by all STAs in the BSS. The bandwidth of the primarychannel may be set and/or limited by a STA, from among all STAs inoperating in a BSS, which supports the smallest bandwidth operatingmode. In the example of 802.11ah, the primary channel may be 1 MHz widefor STAs (e.g., MTC type devices) that support (e.g., only support) a 1MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes.Carrier sensing and/or Network Allocation Vector (NAV) settings maydepend on the status of the primary channel. If the primary channel isbusy, for example, due to a STA (which supports only a 1 MHz operatingmode), transmitting to the AP, the entire available frequency bands maybe considered busy even though a majority of the frequency bands remainsidle and may be available.

In the United States, the available frequency bands, which may be usedby 802.11ah, are from 902 MHz to 928 MHz. In Korea, the availablefrequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the availablefrequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidthavailable for 802.11ah is 6 MHz to 26 MHz depending on the country code.

FIG. 1D is a system diagram illustrating the RAN 113 and the CN 115according to an embodiment. As noted above, the RAN 113 may employ an NRradio technology to communicate with the WTRUs 102 a, 102 b, 102 c overthe air interface 116. The RAN 113 may also be in communication with theCN 115.

The RAN 113 may include gNBs 180 a, 180 b, 180 c, though it will beappreciated that the RAN 113 may include any number of gNBs whileremaining consistent with an embodiment. The gNBs 180 a, 180 b, 180 cmay each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the gNBs 180 a, 180 b, 180 c may implement MIMO technology. For example,gNBs 180 a, 108 b may utilize beamforming to transmit signals to and/orreceive signals from the gNBs 180 a, 180 b, 180 c. Thus, the gNB 180 a,for example, may use multiple antennas to transmit wireless signals to,and/or receive wireless signals from, the WTRU 102 a. In an embodiment,the gNBs 180 a, 180 b, 180 c may implement carrier aggregationtechnology. For example, the gNB 180 a may transmit multiple componentcarriers to the WTRU 102 a (not shown). A subset of these componentcarriers may be on unlicensed spectrum while the remaining componentcarriers may be on licensed spectrum. In an embodiment, the gNBs 180 a,180 b, 180 c may implement Coordinated Multi-Point (CoMP) technology.For example, WTRU 102 a may receive coordinated transmissions from gNB180 a and gNB 180 b (and/or gNB 180 c).

The WTRUs 102 a, 102 b, 102 c may communicate with gNBs 180 a, 180 b,180 c using transmissions associated with a scalable numerology. Forexample, the OFDM symbol spacing and/or OFDM subcarrier spacing may varyfor different transmissions, different cells, and/or different portionsof the wireless transmission spectrum. The WTRUs 102 a, 102 b, 102 c maycommunicate with gNBs 180 a, 180 b, 180 c using subframe or transmissiontime intervals (TTIs) of various or scalable lengths (e.g., containingvarying number of OFDM symbols and/or lasting varying lengths ofabsolute time).

The gNBs 180 a, 180 b, 180 c may be configured to communicate with theWTRUs 102 a, 102 b, 102 c in a standalone configuration and/or anon-standalone configuration. In the standalone configuration, WTRUs 102a, 102 b, 102 c may communicate with gNBs 180 a, 180 b, 180 c withoutalso accessing other RANs (e.g., such as eNode-Bs 160 a, 160 b, 160 c).In the standalone configuration, WTRUs 102 a, 102 b, 102 c may utilizeone or more of gNBs 180 a, 180 b, 180 c as a mobility anchor point. Inthe standalone configuration, WTRUs 102 a, 102 b, 102 c may communicatewith gNBs 180 a, 180 b, 180 c using signals in an unlicensed band. In anon-standalone configuration WTRUs 102 a, 102 b, 102 c may communicatewith/connect to gNBs 180 a, 180 b, 180 c while also communicatingwith/connecting to another RAN such as eNode-Bs 160 a, 160 b, 160 c. Forexample, WTRUs 102 a, 102 b, 102 c may implement DC principles tocommunicate with one or more gNBs 180 a, 180 b, 180 c and one or moreeNode-Bs 160 a, 160 b, 160 c substantially simultaneously. In thenon-standalone configuration, eNode-Bs 160 a, 160 b, 160 c may serve asa mobility anchor for WTRUs 102 a, 102 b, 102 c and gNBs 180 a, 180 b,180 c may provide additional coverage and/or throughput for servicingWTRUs 102 a, 102 b, 102 c.

Each of the gNBs 180 a, 180 b, 180 c may be associated with a particularcell (not shown) and may be configured to handle radio resourcemanagement decisions, handover decisions, scheduling of users in the ULand/or DL, support of network slicing, dual connectivity, interworkingbetween NR and E-UTRA, routing of user plane data towards User PlaneFunction (UPF) 184 a, 184 b, routing of control plane informationtowards Access and Mobility Management Function (AMF) 182 a, 182 b andthe like. As shown in FIG. 1D, the gNBs 180 a, 180 b, 180 c maycommunicate with one another over an Xn interface.

The CN 115 shown in FIG. 1D may include at least one AMF 182 a, 182 b,at least one UPF 184 a, 184 b, at least one Session Management Function(SMF) 183 a, 183 b, and possibly a Data Network (DN) 185 a, 185 b. Whileeach of the foregoing elements are depicted as part of the CN 115, itwill be appreciated that any of these elements may be owned and/oroperated by an entity other than the CN operator.

The AMF 182 a, 182 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N2 interface and may serve as acontrol node. For example, the AMF 182 a, 182 b may be responsible forauthenticating users of the WTRUs 102 a, 102 b, 102 c, support fornetwork slicing (e.g., handling of different PDU sessions with differentrequirements), selecting a particular SMF 183 a, 183 b, management ofthe registration area, termination of NAS signaling, mobilitymanagement, and the like. Network slicing may be used by the AMF 182 a,182 b in order to customize CN support for WTRUs 102 a, 102 b, 102 cbased on the types of services being utilized WTRUs 102 a, 102 b, 102 c.For example, different network slices may be established for differentuse cases such as services relying on ultra-reliable low latency (URLLC)access, services relying on enhanced massive mobile broadband (eMBB)access, services for machine type communication (MTC) access, and/or thelike. The AMF 162 may provide a control plane function for switchingbetween the RAN 113 and other RANs (not shown) that employ other radiotechnologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP accesstechnologies such as WiFi.

The SMF 183 a, 183 b may be connected to an AMF 182 a, 182 b in the CN115 via an N11 interface. The SMF 183 a, 183 b may also be connected toa UPF 184 a, 184 b in the CN 115 via an N4 interface. The SMF 183 a, 183b may select and control the UPF 184 a, 184 b and configure the routingof traffic through the UPF 184 a, 184 b. The SMF 183 a, 183 b mayperform other functions, such as managing and allocating UE IP address,managing PDU sessions, controlling policy enforcement and QoS, providingdownlink data notifications, and the like. A PDU session type may beIP-based, non-IP based, Ethernet-based, and the like.

The UPF 184 a, 184 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N3 interface, which may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between the WTRUs 102a, 102 b, 102 c and IP-enabled devices. The UPF 184, 184 b may performother functions, such as routing and forwarding packets, enforcing userplane policies, supporting multi-homed PDU sessions, handling user planeQoS, buffering downlink packets, providing mobility anchoring, and thelike.

The CN 115 may facilitate communications with other networks. Forexample, the CN 115 may include, or may communicate with, an IP gateway(e.g., an IP multimedia subsystem (IMS) server) that serves as aninterface between the CN 115 and the PSTN 108. In addition, the CN 115may provide the WTRUs 102 a, 102 b, 102 c with access to the othernetworks 112, which may include other wired and/or wireless networksthat are owned and/or operated by other service providers. In oneembodiment, the WTRUs 102 a, 102 b, 102 c may be connected to a localData Network (DN) 185 a, 185 b through the UPF 184 a, 184 b via the N3interface to the UPF 184 a, 184 b and an N6 interface between the UPF184 a, 184 b and the DN 185 a, 185 b.

In view of FIGS. 1A-1D, and the corresponding description of FIGS.1A-1D, one or more, or all, of the functions described herein withregard to one or more of: WTRU 102 a-d, Base Station 114 a-b, eNode-B160 a-c, MME 162, SGW 164, PGW 166, gNB 180 a-c, AMF 182 a-b, UPF 184a-b, SMF 183 a-b, DN 185 a-b, and/or any other device(s) describedherein, may be performed by one or more emulation devices (not shown).The emulation devices may be one or more devices configured to emulateone or more, or all, of the functions described herein. For example, theemulation devices may be used to test other devices and/or to simulatenetwork and/or WTRU functions.

The emulation devices may be designed to implement one or more tests ofother devices in a lab environment and/or in an operator networkenvironment. For example, the one or more emulation devices may performthe one or more, or all, functions while being fully or partiallyimplemented and/or deployed as part of a wired and/or wirelesscommunication network in order to test other devices within thecommunication network. The one or more emulation devices may perform theone or more, or all, functions while being temporarilyimplemented/deployed as part of a wired and/or wireless communicationnetwork. The emulation device may be directly coupled to another devicefor purposes of testing and/or may performing testing using over-the-airwireless communications.

The one or more emulation devices may perform the one or more, includingall, functions while not being implemented/deployed as part of a wiredand/or wireless communication network. For example, the emulationdevices may be utilized in a testing scenario in a testing laboratoryand/or a non-deployed (e.g., testing) wired and/or wirelesscommunication network in order to implement testing of one or morecomponents. The one or more emulation devices may be test equipment.Direct RF coupling and/or wireless communications via RF circuitry(e.g., which may include one or more antennas) may be used by theemulation devices to transmit and/or receive data.

Although the features and elements described herein consider LTE, LTE-A,New Radio (NR), and/or 5G specific protocols, it should be understoodthat the features and elements described herein are not restricted toLTE, LTE-A, New Radio (NR), and/or 5G specific protocols and may beapplicable to other wireless systems.

In wireless communication systems, a central node (e.g., a gNodeB) mayserve one or more WTRUs. When a central node serves one or more WTRUs,the opportunity to send transport blocks (TBs) to the central node maybe administered by the central node. For example, a gNodeB (gNB) mayschedule a WTRU uplink (UL) transmission by assigning time-frequencyresources (e.g., separate time-frequency resources) to one or more WTRUs(e.g., each WTRU) and/or granting one or more resources (e.g., eachresource) to a WTRU. Such arrangement for UL transmission may bereferred to as grant-based UL transmission.

A gNB may broadcast the presence of one or more time-frequency resourcesand/or allow one or more WTRUs (e.g., a set of WTRUs) to compete for theresources (e.g., each resource), and/or allow access to the resourceswithout an UL grant (e.g., a specific UL grant). Such arrangement (e.g.,in New Radio (NR)) for UL transmission may be referred to as grant-free(GF) UL transmission, or an UL transmission without grant. Theapplication of GF UL transmission may be in ultra-reliable low-latencycommunication (URLLC), massive machine-type communication (mMTC orMMTC), and/or enhanced mobile broadband (eMBB or EMBB) communication.MMTC may enable communication between a large number of low-cost andpower-constrained (e.g., battery-driven) devices intended to supportapplications (e.g., smart metering, logistics, and/or field and bodysensors). URLLC may enable devices and/or machines to reliably (e.g.,ultra-reliably) communicate with very low latency and/or highavailability. Enabling devices and/or machines to communicate withultra-reliability, very low latency, and/or high availability may enableURLLC to provide vehicular communication, industrial control, factoryautomation, remote surgery, smart grids, and/or public safetyapplications. EMBB may provide enhancements to one or more (e.g., avariety) of parameters (e.g., data rate, delay, and coverage) of mobilebroadband access.

GF UL transmission may be performed. One or more of the following mayapply. A gNB may specify GF resources (e.g., via radio resource control(RRC) signaling). The GF resources may be WTRU-specific or may beWTRU-independent. A WTRU may pick a GF resource and/or send a TB on theGF resource. If the WTRU does not receive (e.g., after a period of time)a hybrid automatic repeat request acknowledgment (HARQ-ACK) (e.g., thecorresponding HARQ-ACK for a TB), the WTRU may retransmit the TB (e.g.,may plan to retransmit the TB). The WTRU may retransmit the TB onanother GF resource and/or on a granted resource (e.g., if the gNBgrants a resource). The WTRU may retransmit using GF resources, forexample, until a max number of retries is reached.

In a GF UL transmission, a TB may be transmitted (e.g., transmitted Ktimes) across consecutive resources (e.g., K consecutive GF resources).Such transmissions may be referred to as GF transmissions with Krepetitions. For a GF UL transmission (e.g., for a TB transmission withK repetitions), the repetitions may follow a redundancy-version (RV)sequence that may be configured by WTRU-specific RRC signaling (e.g., tobe a previously known sequence). An RV sequence may include a sequenceof redundancy version values used by a WTRU. In examples, a RV sequencemay include a sequence of one or more repeated redundancy versions(e.g., four repetitions of a redundancy version of 0, such as, [0, 0, 0,0]). In examples, a RV sequence may include a sequence of one or moreredundancy versions where the first and third redundancy version valuesare 0 and the second and fourth are with redundancy version values are 3(e.g., [0, 3, 0, 3]).

There may be an inefficiency in a (e.g., each) GF UL transmission, forexample. The inefficiency may be due to the nature of GF transmissionand/or may depend on the number of WTRUs attempting to use a (e.g.,each) GF resource.

Depending on the application (e.g., URLLC or mMTC) for which the GFoperation is used, there may be a chance (e.g., a low chance or a highchance) of a collision among the WTRUs attempting to access a GFresource. The higher the number of attempting WTRUs, the higher thechance of collision and/or the lower the overall efficiency. The chanceof a collision among the attempting WTRUs may be lowered.

A WTRU may multiplex Uplink Control Information (UCI) with the TB (e.g.,the TB that the WTRU attempts to send using a GF resource). The behaviorof a WTRU, for example, after performing the GF operation, may be usedto determine whether the gNB received (e.g., successfully received) theUCI.

One or more types of GF transmissions (e.g., in NR) may be performed. AgNB may specify GF resources using one or more of the following. A gNBmay specify a GF resource via a Radio Resource Control (RRC)configuration (e.g., reconfiguration) without L1 signaling (e.g., Type1). A gNB may specify a GF resource via RRC configuration with L1signaling (e.g., Type 2). A gNB may specify a GF resource via RRCconfiguration with L1 signaling (e.g., that may modify one or moreRRC-configured parameters) (e.g., Type 3).

A grant-free (GF) resource may be selected by one or more WTRUs. Forexample, a WTRU selecting a GF resource from one or more (e.g., a setof) GF resources may perform an UL GF transmission. One or more of thefollowing may apply. A WTRU may receive a HARQ-NACK for a TB that hasbeen sent (e.g., previously sent) via a GF operation. The WTRU may notreceive a HARQ-ACK or a HARQ-NACK for a TB transmission that has beensent. The WTRU may attempt to send the same TB (e.g., resend the sameTB) or another TB (e.g., if the WTRU receives a HARQ-NACK, or the WTRUdoes not receive a HARQ-NACK or HARQ-ACK). The WTRU may choose the nextresource for the UL GF transmission. A WTRU may attempt) to send the ULGF transmission on a GF resources that other WTRUs are also attemptingto transmit on, such as in mMTC applications, which may increase thechance of a collision among the WTRUs.

The WTRU may retransmit a pending TB on a GF resource (e.g., the nextimmediately available GF resource). For example, the WTRU may retransmitthe pending TB on the next immediately available GF resource (e.g.,because doing so may lower the potential delay). If two or more WTRUs(e.g., all WTRUs) that have collided during the previous GF resource(e.g., which may lead to HARQ-NACK or DRX) retransmit their pending TBon the next (e.g., immediately next) GF resource(s), the chance ofanother collision may increase.

An opportunistic resource selection for a GF retransmission may beperformed. An example of an opportunistic resource selection for GFretransmission is shown in FIG. 2 . For example, as shown in FIG. 2 , ifa GF transmission by a WTRU is unsuccessful, the WTRU may choose anupcoming GF resource to retransmit its pending TB. One or more (e.g.,two) WTRUs may attempt to send their pending TB on GF resource 1 in FIG.2 . A gNB may be unsuccessful in decoding the TBs (e.g., any of theTBs), for example, due to a collision. The gNB may be unable to identifywhich WTRUs have used the GF resource 1. The gNB may be unable to sendHARQ feedback to the WTRUs. A WTRU may determine to retransmit thepending TB on the next available (e.g., next immediately available) GFresource (e.g., GF resource 2), for example, because doing so wouldlower the delay (e.g., potential delay). If a WTRU determines toretransmit the pending TB on the next available (e.g., next immediatelyavailable) GF resource, there may be a low (e.g., no) chance of acollision. If two or more (e.g., all) WTRUs that have collided duringthe previous GF resource 1 retransmit their pending TB on the sameresource, there may be an increase in the chance of a collision.

The WTRU may not retransmit on one or more subsequent GF resources(e.g., one or more immediately subsequent GF resources) and/or mayretransmit the pending TB in an opportunistic manner (e.g., to lower thechance of collision). The WTRU may back off from retransmission, forexample, by skipping a random number of GF resources (e.g., a back offvalue) before initiating a retransmission. Backing off for a randomnumber of GF resources may lead to distributing the attempting WTRUsover a longer period, for example, because the random number may bechosen from a pre-defined range (e.g., range of back off values) and/ormay be derived (e.g., drawn) according to a probability (e.g.,non-deterministically) such that the chance of two or more WTRUsderiving (e.g., drawing) the same random number (e.g., the same back offvalue) is minimal. For example, the back off counter (e.g., back offvalue) may be derived (e.g., drawn) uniformly from a pre-defined range(e.g., 0 to T₁). As T₁ becomes larger (e.g., as the back off rangebecomes larger), the chance of a collision (e.g., another collision) maybe lowered, for example, among the contending WTRUs. For example, ifT₁=3, two WTRUs (e.g., two WTRUs that have collided in a previousattempt to transmit during a given GF resource) may be more likely(e.g., more likely than if T₁=1) to derive (e.g., draw) different backoff values from a range (e.g., a range of back off values that includes0, 1, 2, 3) and/or may be more likely to send on separate GF resources.The two WTRUs may derive (e.g., draw) the same number (e.g., back offvalue) from the range (e.g., a range of back off values that includes 0,1, 2, 3). If the derived (e.g., drawn) numbers are the same (e.g., theback off values are the same), the two WTRUs may transmit (e.g.,retransmit) on the same GF resource, for example, which may lead to a(e.g., another) collision. If the transmission (e.g., retransmission)fails (e.g., also fails), a next GF resource for transmission may bechosen (e.g., chosen again). The next GF resource for transmission maybe chosen randomly from a range (e.g., 0 to T₂) that may be wider (e.g.,larger) than the previous range (e.g., T₂ may be 2×T₁+1). For example,if T₁=3, then T₂=7, where a WTRU (e.g., each WTRU) of the two or moreWTRUs that have collided in the previous GF UL transmission may derive(e.g., draw) a back off value randomly with a uniform distribution froma range (e.g., a range of back off values that includes 0, 1, 2, 3, 4,5, 6, 7). The range of the back off values may increase. As the range ofback off values increases, the likelihood that different back offcounters are derived (e.g., drawn) by contending WTRUs and/or thelikelihood that separate GF resources are used by the contending WTRUsto send a transmission (e.g., subsequently send a transmission) mayincrease. As described herein, a backoff range may be referred to ascontention window size (CWS).

A WTRU may initiate GF transmission or retransmission, for example, byderiving (e.g., drawing) a back off value (e.g., denoted by t) from arange of back off values (e.g., from T₀ to T_(i)), skipping resources(e.g., skipping the next t−1 GF resources), and/ortransmitting/retransmitting on a resource (e.g., the t^(th) GFresource). To may be equal to 0 (e.g., the first transmission may have azero back off counter), T₁ may be equal to 3, and T_(i) may be equal to2×T_(i−1)+1 (e.g., leading to T₂=7, T₃=15, etc.). A non-zero back offcounter may be used for T₀, for example, for the first transmission(e.g., T₀=3, and T_(i)=2×T_(i−1)+1, which may lead to T₀=3, T₁=7, T₂=15,etc.). An example may include a coefficient, which may double the backoff value range (e.g., after a collision). The increase may be performedwith a different coefficient (e.g., 3, which may triple the back offvalue range), for example, such that T_(i)=3×(T_(i−1)+1)−1). The backoff value range may increase, for example, to lower the chance ofanother collision among two or more contending WTRUs. The sequence ofT_(i) values may be pre-defined for WTRUs (e.g., some or all WTRUs), ormay be communicated via RRC signaling, etc. A WTRU (e.g., each WTRU) maypick (e.g., may randomly pick) the T_(i) value according to whether itis transmitting for the first time, retransmitting for the first time,retransmitting for the second time, etc. (e.g., such that the backoffrange may be different for first transmission, first retransmission,second retransmission, etc.). The sequence of T_(i) values may beprovided to each WTRU via WTRU-specific RRC signaling and the sequenceof one WTRU may be different from another WTRU, e.g., depending on thepriority given to each WTRU (e.g., WTRUs running low-latencyapplications may be prioritized over WTRUs running MMTC applications).

The values of T₀, T₁, T₂, etc., and/or the probability that a value isderived (e.g., drawn) from may be predefined (e.g., predefined in thespecification) and/or may be signaled (e.g., signaled by RRC). The gNBmay customize the parameters (e.g., the parameters that indicate thevalues of T₀, T₁, T₂, etc. and/or the probability that a value isderived), for example, according to the deployment and/or application.

A WTRU (e.g., each WTRU) may priori select (e.g., or be granted) arandom sub-set of the grant free resources available for transmissionthat may be unique to the WTRU (e.g., each WTRU). A grant free resourcemay be selected for transmission by a WTRU. The WTRU may select thegrant free resource without receiving a unique and/or explicit grantfrom a gNB. For example, rather than the gNB allocating a set ofresources to WTRUs (e.g., all the grant free WTRUs), a WTRU (e.g., eachWTRU) may priori select (e.g., or be granted) a random sub-set of thegrant free resources available for transmission. The sub-set of grantfree resources may be unique to the WTRU (e.g., each WTRU). Upon failureof an initial transmission, the WTRU may send a retransmission on aresource (e.g., the next uniquely available grant free resource from thesub-set of grant free resources). The randomization of the WTRU specificgrant free resource (e.g., the sub-set of grant free resources unique tothe WTRU) may reduce the probability that a collision occurs betweensubsequent transmissions of the transmitting WTRUs.

It may be determined whether a GF transmission is successful orunsuccessful. When a WTRU sends a TB to a gNB (e.g., the WTRU's gNB),the WTRU may receive an HARQ-ACK or HARQ-NACK, for example, after thetransmission (e.g., in response to the transmission). The timing betweenan UL transmission and the corresponding HARQ feedback (e.g., expectedto be sent by the gNB to the WTRU) may be expressed by a parameter thatmay be obtained from one or more fields in the DCI, or may be configuredby an RRC parameter.

In GF UL transmission, the WTRU may not receive or may not detect aHARQ-ACK or a HARQ-NACK (e.g., due to the collision of two or moretransmissions by WTRUs transmitting on the same GF resource). After acertain time (e.g., an acknowledgment time), the WTRU may determine thata previously sent TB was not received by the gNB and/or may attempt toretransmit the TB using a GF resource (e.g., the next available GFresource). For GF UL transmission, the timing between a GF ULtransmission and the expected HARQ feedback may be expressed by aparameter (e.g., an acknowledgement time) that may be carried in one ormore fields in the DCI or may be specified by RRC.

One or more WTRUs may attempt to use GF resources (e.g., available GFresources) in one or more (e.g., a few) consecutive slots. If WTRUs(e.g., all WTRUs) wait for the same duration of time before determiningthat the previous GF transmission was unsuccessful, the WTRUs (e.g., allthe WTRUs) may target the same GF resource for transmission (e.g., thenext immediately available GF resource), for example, to perform aretransmission. A fixed time duration for WTRUs (e.g., all WTRUs) todetermine whether a previous GF transmission is unsuccessful may lead toa higher chance of a collision on the next GF resource used fortransmission. A WTRU may use a corresponding time duration (e.g.,waiting time) that is different from another WTRU. Such a varyingwaiting time may distribute the retransmission attempts by the WTRUs,for example, over a range of two or more (e.g., several) GF resourcesand/or over two or more (e.g., several) slots. In a GF UL transmission,the timing between a GF UL transmission and a time (e.g., a maximumtime) that the corresponding HARQ feedback is to be received (e.g., isexpected to be received) may be expressed by a parameter (e.g., that maybe carried in one or more fields in the DCI and/or specified by aWTRU-specific RRC). Such time interval may be different from a WTRU andanother WTRU. The gNB may define the time interval. For example, the gNBmay assign a time duration to one or more WTRU (e.g., each WTRU). Thismay be a gNB directed method. The gNB may specify a range of time fromwhich the WTRU may pick (e.g., may randomly pick) a value and/or maychoose the value to be the timing between a GF UL transmission andmaximum time that the corresponding HARQ feedback is to be received(e.g., is expected to be received). The gNB specifying the range of timeand/or choosing the value may be WTRU autonomous (e.g., more WTRUautonomous). The WTRU may provide feedback of (e.g., may need to providefeedback of) the value to the gNB. Feeding back the value to the gNB mayreduce the amount of grant free blind decoding, for example, when thegNB is able to identify the WTRU and not decode the payload.

The range of time intervals may be determined by parameters (e.g., thetraffic class). For example, low latency traffic may have a smallerrange and/or latency tolerant traffic may have a larger range. A WTRUmay have a range (e.g., a single range) that may be determined based onthe WTRU application type (e.g., the range for URLLC applicationtype<the range of a eMBB application type<the range for a mMTCapplication type). A WTRU may have two or more (e.g., multiple) rangesthat may be selected based on the type of traffic to be sent.

One or more GF resources may be sensed, for example, to reducecollisions. In GF UL transmissions, one or more WTRUs may attempt tosend their pending TB on the same GF resource. For example, one or moreWTRUs may attempt to send their pending TB on the same GF resourcebecause the GF resources may be up for grabs by one or more WTRUs (e.g.,any WTRU) that is configured to perform GF UL transmission. An attemptby multiple WTRUs to use the same GF resources may cause a collisionamong the WTRUs (e.g., unsuccessful transmissions), for example, whichmay lead to none of the TB of the WTRUs being decoded (e.g., beingdecoded successfully). WTRUs may avoid such collisions, for example, bysensing the resource (e.g., the GF resource) to find out whether anotherWTRU is using the resource, for example, before attempting to send theirpending TB during the same GF resource.

One or more time-domain GF resources may be sensed. A WTRU (e.g., eachWTRU) that attempts to use a GF resource may choose a beginning portionof the resource to perform resource sensing, for example, to find out anavailability of the resource. If no use of the resource is detected(e.g., if the WTRU determines that no other WTRU is using the resource),the WTRU may decide to send its pending TB on the remaining portion ofthe GF resource (e.g., after processing). Sensing the medium may includeperforming energy detection (ED), for example, during the sensingportion. FIG. 3 shows an example where the attempting WTRU senses thefirst symbols of the GF resource (e.g., the first three symbols of theGF resource). In order to benefit from such behavior, an attempting WTRU(e.g., each attempting WTRU) may choose a sensing interval that may bedifferent from the sensing interval of another attempting WTRU. Forexample, a WTRU may determine to sense the availability of thegrant-free resource during the WTRU's first few OFDM symbols (e.g.,first three symbols as in FIG. 3 ) and/or throughout the bandwidth ofthe grant-free resource. If it is detected that no other WTRU is usingthe resource (e.g., using energy-detection), the WTRU may determine tosend the WTRU's pending TB on the remaining portion of the GF resource,for example, after processing.

A WTRU (e.g., each WTRU) may choose a number (e.g., a random number) ofsymbols, for example, that may be derived (e.g., drawn) using a prioriknown probability distribution. For example, WTRUs (e.g., all attemptingWTRUs) may derive (e.g., draw) a number (e.g., a random number)uniformly from a range (e.g., 0, 1, 2, 3, 4) and/or may perform theresource sensing during the derived number of symbols and/or throughoutthe bandwidth of the GF resource. FIG. 4 shows an example where threeWTRUs attempt to use a grant-free resource and the WTRUs (e.g., eachWTRU) uniformly derive (e.g., draws) a value (e.g., a single value) froma priori-known range (e.g., 0, 1, 2, 3, 4). Referring to FIG. 4 one ormore of the following may apply. A sensing interval for WTRU1 may be 4symbols, a sensing interval for WTRU2 may be 3 symbols, and/or a sensinginterval for WTRU3 may be 1 symbol. The three WTRUs may pseudo-randomly(e.g., according to a distribution) derive (e.g., draw) a number n froma priori-known range (e.g., 0, 1, 2, 3, 4) and/or may sense theavailability of the resource during the first n symbols and throughoutthe bandwidth of the grant-free resource. WTRU1 may sense the mediumduring the first four OFDM symbols of the GF resource. WTRU2 may sensethe medium during the first three OFDM symbols of the GF resource. WTRU3may sense the medium during the first OFDM symbol of the GF resource.WTRU3 may be the first WTRU that finds the medium is available and/ormay attempt to send the WTRU's pending TB, for example, on the remainingportion of the GF resource (e.g., after processing). WTRU1 and WTRU2(e.g., after sensing the medium for the duration that is expected) maydetermine that the GF resource is in use and/or may refrain from usingthe GF resource. Two or more WTRUs may derive (e.g., draw) the samenumber and/or may sense the resource for the same duration, which maylead to collision among the WTRUs. The chance for such outcome decreasesas the resource sensing range increases.

Two or more WTRUs may attempt to use a GF resource (e.g., the same GFresource). WTRU3 may not attempt to use the GF resource (e.g., may notperform the resource sensing). WTRU2 and WTRU1 may sense the medium. Forexample, WTRU2 may be the first WTRU that determines that the medium isavailable and/or may send (e.g., attempt to send) the WTRU's pending TBat the remaining portion of the resource (e.g., after processing). WTRU1(e.g., after sensing the medium for the duration (e.g., the expectedduration)) may determine that the GF resource is in use and/or mayrefrain from using the GF resource. If neither WTRU3 nor WTRU2 attemptto use the GF resource (e.g., do not perform the resource sensing), theWTRU1 (e.g., after completion of its sensing period) may determine thatthe GF resource is not in use and/or may transmit its pending TB.

Depending on the sensing performed (e.g., energy detection) and/or theaccuracy of sensing performed by a WTRU (e.g., each WTRU), the WTRU maydetermine earlier (e.g., earlier than the end of its sensing interval)that the GF resource is in use and/or may stop sensing the resource. Forexample, depending on the sensing and/or the accuracy of the sensingperformed by a WTRU, the WTRU may fail to sense the medium is in useand/or may attempt to use the resource, which may cause a collision.

One or more frequency-domain GF resources may be sensed. A WTRU mayperform (e.g., may consistently perform) resource sensing for the samenumber of OFDM symbols (e.g., one OFDM symbol and/or a priori known fewOFDM symbols) and/or for a variable number of resource blocks (RB). FIG.5 shows an example where three WTRUs attempt to use a given grant-freeresource and/or a WTRU (e.g., each WTRU) uniformly derives (e.g., draws)a value (e.g., a single value) from a priori-known range. As illustratedin FIG. 5 , WTRU1, WTRU2, and WTRU3 may perform resource sensing on thesame number of OFDM symbols but for a different number of RBs. Referringto FIG. 5 , one or more of the following may apply. A sensing intervalfor WTRU1 may be 9 RBs (e.g., before a GF transmission). A sensinginterval for WTRU2 may be 7 RBs (e.g., before a GF transmission). Asensing interval for WTRU3 may be 4 RBs (e.g., before a GFtransmission). The three WTRUs may pseudo-randomly derive (e.g., draw)(e.g., per a distribution) a number n from a priori-known range and/ormay sense the availability of the resource during the top n RBs of thefirst OFDM symbol (e.g., or a priori-known first few OFDM symbols).WTRU1 may sense the medium during the top 9 RBs of the GF resource.WTRU2 may sense the medium during the top 7 RBs of the GF resource WTRU3may sense the medium during the top 4 RBs of the GF resource. WTRU3 maybe the first WTRU that finds the medium is available and/or may attemptto send the WTRU's pending TB on the remaining portion of the resource,for example, after processing. WTRU1 and WTRU2 (e.g., after sensing themedium for the duration that is respectively expected) may determinethat the GF resource is in use and/or may refrain from using the GFresource. The range that a WTRU (e.g., each WTRU) derives (e.g., draws)the WTRU's sensing period from may be a priori known (e.g., communicatedvia a parameter by RRC or DCI). The range may be obtained (e.g., mayimplicitly be obtained) by a WTRU (e.g., each WTRU) as a function of thebandwidth of the GF resource. For example, the range may be thebandwidth of the GF resource represented by the number of RBs associatedwith the GF resource. FIG. 5 shows an example in which the rangeincludes (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11). The range may be implicitlyobtained from the bandwidth of the GF resource which is 11 RBs.

Two or more WTRUs may attempt to use a GF resource (e.g., the same GFresource). WTRU3 may not attempt to use the GF resource (e.g., may notbe performing the resource sensing). WTRU2 and WTRU1 may be sensing themedium. WTRU2 may be the first WTRU that determines that the medium isavailable and/or may attempt to send the WTRU's pending TB at theremaining portion of the resource (e.g., after processing). WTRU1 (e.g.,after sensing the medium for the duration (e.g., the expected duration))may determine that the GF resource is in use and/or may refrain fromusing the GF resource. If neither WTRU3 nor WTRU2 attempt to use the GFresource (e.g., do not perform the resource sensing), the WTRU1 (e.g.,after completion of its sensing period) may determine that the GFresource is not in use and/or may transmit its pending TB.

A two-dimensional time-frequency GF resource may be sensed. A WTRU mayperform the resource sensing for a variable number (e.g., derivedpseudo-randomly from a priori known time-interval) of OFDM symbols(e.g., first OFDM symbols) of the GF resource and/or for a variablenumber (e.g., derived pseudo-randomly from a priori known RB-interval)of top resource blocks. For example, a time-interval may be (0, 1, 2)and/or a RB-interval may be (0, 1, 2, 3, 4). The WTRU may derive (e.g.,draw) a number pseudo-randomly from the time-interval, which may be thetime duration of the sensing interval. The WTRU may derive (e.g., draw)a number pseudo-randomly from the RB-interval, which may be thefrequency bandwidth of the sensing interval. If the WTRU determines theresource is not in use (e.g., using energy-detection) during the sensinginterval, the WTRU may send the WTRU's pending TB, for example, at theremaining portion of the GF resource after processing. A set of resourcesensing areas may be priori known by one or more WTRU(s) (e.g., allWTRUs) and/or a WTRU may pseudo-randomly select an area to performresource sensing. A resource sensing area may include rectangular timeand frequency interval, such as (t,f) where t may be in units of OFDMsymbol and/or f may be in units of RBs.

The resource sensing areas in FIG. 3 may include one or more of thefollowing. t may be pseudo-randomly derived (e.g., drawn) by a WTRU froma priori distribution. t may be different for two or more WTRUs. Forexample, a WTRU attempting to use the GF resource may have a t that maybe different from another WTRU. f may be fixed for one or more (e.g.,all) WTRUs attempting to use the GF resource (e.g., f may be equal tothe bandwidth of the GF resource, for example, all the RBs of the GFresource).

The resource sensing areas in FIG. 4 may include one or more of thefollowing. f may be pseudo-randomly derived (e.g., drawn) by a WTRU froma priori distribution and/or f may be one or more RBs. f may bedifferent in two or more WTRUs. For example, a WTRU attempting to usethe GF resource may have an f that may be different from an f in anotherWTRU. t may be fixed for WTRUs (e.g., all WTRUs) attempting to use theGF resource (e.g., t may be equal to one or more OFDM symbols).

The sensing areas may be 2-D time-frequency areas, for example, wherethe sensing area for a WTRU may differ from another WTRU in time and/orfrequency domain. A set of sensing areas may be a priori known by one ormore WTRU(s) (e.g., all WTRUs (e.g., (t_(i), f_(i)) for one or more(e.g., all) the sensing areas is a priori identified by gNB and/or knownto one or more (e.g., all) WTRUs). The WTRU may select a sensing areafrom the set. The set of sensing areas may be designed and/or may benested. A smallest sensing area may be a subset of one or more sensingareas (e.g., all other sensing areas). A second smallest sensing areamay be a subset of one or more other sensing areas (e.g., all othersensing areas besides the smallest sensing area), etc. The structure(e.g., the nested structure) of the sensing areas may allow for thedetermination (e.g., an unambiguous inference) of whether the resourceis in use. For example, a fixed payload size carrying the sensing areasin the format of a bitmap may be used to indicate sensing areas withinthe GF resource. The two-dimensional bitmap may indicate one or morefrequency-time areas/partitions within the GF resource.

The resource sensing may be performed in time-domain and/or RB-domain,for example, according to a sensing interval, which may bepseudo-randomly derived (e.g., drawn) from a priori-known distribution.One or more WTRUs may be prioritized to use a minimum sensing interval(e.g., performing no resource sensing). For example, a WTRU that isconfigured for low-latency applications may be configured by RRC toperform no sensing (e.g., as if the WTRU's sensing interval is zero)and/or the WTRU may attempt to use a GF resource without sensing. WTRUs(e.g., WTRUs that perform latency-tolerant applications, such as mMTC)may be configured to perform resource sensing. A WTRU with a certainapplication (e.g., a low-latency application) may get a higher priority,for example, compared to other WTRUs. The priori range that WTRU'sderive (e.g., draw) a number from (e.g., pseudo-randomly derive a numberfrom) may start from a non-zero number, for example, to prioritize thehigh-priority WTRUs. Prioritization may be performed based on or morecriteria. In examples, the prioritization may be based on applicationsperformed by a WTRU (e.g., low-latency vs mMTC applications).

For resource sensing, the number of resource elements (REs) from the GFresource that a WTRU uses for transmission of a TB may be variableand/or may not be known in advance (e.g., due to the sensing interval).The sensing interval may be a number that is pseudo-randomly derived.One or more of the following may apply (e.g., which may address the lackof knowledge).

The WTRU may prepare the TB, for example, as if there is no resourcesensing. If the WTRU determines that the GF resource is not in use(e.g., after performing the resource sensing), the WTRU may rate matchthe prepared TB and/or send the rate-matched TB.

Where the outcome of the sensing interval is a few symbols (e.g., asensing interval that leads to a few medium sensing interval), the WTRUmay prepare the pending TB with various rate-matching assumptions. Thevarious rate-matching assumptions of the TB may be based on an outcome.For example, a sensing range may be (0, 2, 4) and a WTRU maypseudo-randomly derive (e.g., draw) 0, 2, or 4. Before using the GFresource, the WTRU may rate-match WTRU's pending TB, e.g., for possiblesensing interval outcomes. One or more of the following may apply. TheWTRU may prepare a rate-matched TB as if there is no sensing (e.g.,corresponding to an outcome of 0 derived for the sensing interval). TheWTRU may prepare a rate-matched TB with the remaining REs as if thesensing interval is 2. The WTRU may prepare a rate-matched TB with theremaining REs as if the sensing interval is 4. When the WTRU approachesthe GF resource and/or pseudo-randomly derives (e.g., draws) from therange (0, 2, 4), the WTRU may have the rate-matched TB for an outcomeready.

The gNB may determine (e.g., uniquely determine) the rate-matchingvalue, for example, because the gNB may know what portion of the GFresource has not been used (e.g., what was not used by the WTRU forresource sensing). The gNB may obtain (e.g., implicitly obtain ordetermine) the size of the resource sensing area (e.g., the number ofOFDM symbols for the whole bandwidth of the GF resource, the number ofRBs for a number (e.g., fixed number) of OFDM symbols, and/or the numberof OFDM symbols and number of RBs). The gNB may obtain (e.g.,subsequently obtain or determine) the portion of the resource that wasused for transmission of the WTRU's TB and/or obtain (e.g., subsequentlyobtain or determine) the associated rate-matching ratio.

The WTRU may be configured with one or more of offset values by RRCsignaling wherein a (e.g., each) offset value may be used by the WTRU tocompute the amount of REs for the corresponding sensing range. The WTRUmay consider the UL waveforms (e.g., OFDM vs. DFT-s-OFDM) and/ordifferent UCI multiplexing mechanisms, for example, for determining theoffset values.

The WTRU may be configured to perform resource sensing on the first fewsymbols of a slot, e.g. on the first OFDM symbol, or the first two OFDMsymbols. If the WTRU is configured to perform resource sensing on thefirst few symbols of a slot, the WTRU may determine (e.g., implicitlydetermine) the first OFDM symbol within the slot available for UL GFtransmission (e.g., the remaining portion of the GF resource—PUSCH—bythe WTRU). For example, if the WTRU is performing the resource sensingduring the first M OFDM symbols, the WTRU may determine that the GFPUSCH may be transmitted in the next K symbols (M+1, M+2, . . . , M+K)OFDM symbol. K may be a parameter, for example, in terms of the numberof OFDM symbol(s), which may depend on the WTRU capability. For example,for a WTRU with high capability K=1 (e.g., which may indicate the WTRUmay transmit the UL GF PUSCH in the very next OFDM symbol afterperforming resource sensing). The WTRU may follow the slot-formatconfiguration indicated in the slot format indicator (SFI) for theremaining symbols of the slot.

UCI multiplexing may be performed during GF transmission. A WTRU maytake advantage of a grant-based resource and/or may multiplex UCI, forexample, including Channel State Information (CSI), Channel QualityIndicator (CQI), Rank Indicator (RI), and/or the HARQ ACK/NACKinformation along the TB. The behavior of a WTRU may change during a GFtransmission, for example, when the WTRU attempts to multiplex UCIinformation on the PUSCH.

An adaptive coding rate may be performed for UCI multiplexing. Theprocessing performed by the WTRU (e.g., required to be performed by theWTRU) during UCI multiplexing may be agnostic of whether the ULtransmission is grant-based or grant-free. The processing used for UCImultiplexing may be used during GF UL transmission. For GF transmission,the GF resource may be subject to interference and/or a collision. Toaddress higher interference during the GF UL transmission, theredundancy-version (RV) may be adjusted and/or the TB may berate-matched, for example, so that the multiplexed UCI may be encodedwith a lower-rate coding. In GF UL transmission with K repetitions(e.g., where a UCI is multiplexed with a TB), the UCI info may bemultiplexed using a lower rate code (e.g., compared to the previoustransmission in the sequence of K transmissions). A lower rate code maybe associated with a higher amount of redundancy. In a GF transmissionwith K repetitions, the UCI may be encoded with a lower-rate code in thesecond repetition, for example, compared to the first repetition. TheUCI may be encoded with a lower-rate code in the third repetition, forexample, compared to the second repetition, etc. To ensure that the gNBis aware of the coding rate used by the WTRU, a set of predefined ratematching/coding rate parameters may be specified, for example, whereinthe WTRU may use the set of predefined rate matching/coding rateparameters sequentially during the TB (re)transmission with Krepetitions. For example, the WTRU may follow a coding rate sequence,which may be configured by WTRU-specific RRC signaling to be {½, ⅓, ¼}.The WTRU may use a different beta-offset value for a (re)transmission(e.g., each (re)transmission), for example, to compute the amount of REsfor a (e.g., each) respective UCI to be multiplexed during GF UL(re)transmissions. For example, the WTRU may follow a beta-offsetsequence which may be configured by WTRU-specific RRC signaling to be{β_(offset,0) ^(HARQ-ACK), β_(offset,1) ^(HARQ-ACK), β_(offset,2)^(HARQ-ACK)}. The beta-offset for the first transmission may be smallerthan the beta-offset for the second transmission, etc.

The WTRU may wait for the HARQ feedback of the WTRU's GF UL transmission(e.g., for a waiting time). While the WTRU is waiting for the HARQfeedback of its GF UL transmission, if a PUCCH resource is assigned tothe WTRU, the WTRU may retransmit the UCI (e.g., regardless of whetherthe prior GF UL transmission was successful). If a collision happensduring the GF transmission of the TB with multiplexed UCI, the WTRU mayreceive a HARQ-NACK or may not receive HARQ feedback. Themultiplexed-UCI may not be received by the gNB and/or may beretransmitted (e.g., in an upcoming PUCCH opportunity, if any;multiplexed by a grant-based PUSCH resource; and/or retransmitted inanother GF transmission).

Priority based UCI multiplexing may be performed. If the transmission ofa UCI (e.g., HARQ ACK) by the WTRU has a higher priority than the GFtransmission (e.g., for a given slot), the WTRU may drop the GFtransmission (e.g., CSI or CQI) on PUSCH and/or may send the HARQ-ACK(e.g., only the HARQ-ACK) in the PUCCH. The WTRU may initiate (e.g.,immediately initiate) the GF transmission on the grant free resource onPUSCH in the following slot. If the transmission of a UCI (e.g.,periodic/semi-persistent CSI reports) by the WTRU has a lower prioritythan the GF data transmission (e.g., for a given slot), the WTRU maydrop the periodic/semi-persistent CSI reports and/or proceed with the GFtransmission of data on PUSCH and/or multiplex theperiodic/semi-persistent CSI reports with the data and transmit on theGF resource on PUSCH. If the WTRU has dropped the UCI, the WTRU maycontinue with the transmission of the periodic/semi-persistent CSIreports in the next allocated PUCCH resource. The gNB may determine(e.g., blindly determine) the WTRU behavior, for example, by detecting(e.g., simultaneously detecting) PUCCH and/or the GF PUSCH resources. Ifthe gNB detects PUSCH (e.g., while expecting UCI transmission by theWTRU on the PUCCH) the gNB may determine that the WTRU is multiplexingthe UCI with the data and/or transmitting the UCI and the data on the GFresources on PUSCH.

The priority of the UCI transmissions may be configured by RRC. Forexample, the WTRU may determine that the WTRU is to (e.g., needs to)multiplex the HARQ-ACK with the data, for example, on a GF resourceand/or not drop the HARQ-ACK if a predefined parameter (e.g.,simultaneousAckNackAndData) provided by higher layers is set TRUE. TheWTRU may determine that the WRTU is to drop (e.g., needs to drop)periodic/semi-persistent CSI report(s) and/or not multiplex CSIreport(s) with the data on the GF resource, for example, if a predefinedparameter (e.g., simultaneousCSIAndData) provided by higher layers isnot set TRUE.

UCI multiplexing may be conditioned on the HARQ feedback. If for theinitial transmission, the WTRU has multiplexed the UCI with data and/ortransmitted on the GF UL resource and/or receives NACK from the gNB, theWTRU may not have a good coverage and/or neither the UCI nor the TB mayhave successfully been detected at the gNB. The WTRU may determine(e.g., autonomously determine) to drop the UCI and/or data for the GFretransmissions/repetitions, for example, according to the priority ofthe UCI contents. If the WTRU drops the UCI, the code rate for the GF TBretransmissions may be lowered, for example, which may result in ahigher chance of successful detection of the TB at the gNB. If the WTRUdrops the data, the UCI transmission by the WTRU may be on the PUCCH,for example, which may have a higher probability of detection at thegNB.

If for the initial transmission, the WTRU multiplexed the UCI with dataand/or transmitted on the GF UL resource and/or receives ACK from thegNB, the WTRU may have a good coverage and UCI and/or TB may have beendetected (e.g., successfully been detected) at the gNB. The WTRU maydetermine (e.g., autonomously determine) to multiplex the UCI, forexample, with data for the GF retransmissions/repetitions (e.g.,regardless of the priority of the UCI contents). The WTRU may not drop aUCI and/or may multiplex (e.g., always multiplex) UCI with data in theconsequent GF retransmissions/repetitions.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

What is claimed is:
 1. A method for transmitting uplink controlinformation (UCI) comprising: a wireless transmit receive unit (WTRU)receiving a radio resource control (RRC) message, wherein the RRCmessage comprises information indicating physical uplink shared channel(PUSCH) resources for the WTRU, and the RRC message indicates whether ornot uplink control information (UCI) can be multiplexed with data on thePUSCH resources; the WTRU determining to transmit first UCI during atime period that overlaps with a transmission opportunity associatedwith the PUSCH resources; and the WTRU transmitting the first UCI,wherein the WTRU multiplexes the first UCI on the PUSCH resourcesassociated with the transmission opportunity if the RRC messageindicates that UCI can be multiplexed with data on the PUSCH resources,and the WTRU transmits the first UCI on one or more physical uplinkcontrol channel (PUCCH) resources if the RRC message indicates that UCIcannot be multiplexed with data on the PUSCH resources.
 2. The method ofclaim 1, wherein the first UCI comprises hybrid automatic repeat request(HARQ)/acknowledgment (ACK) information.
 3. The method of claim 1,wherein the WTRU does not transmit the first UCI using the PUSCHresources during the transmission opportunity if the RRC messageindicates that UCI cannot be multiplexed with data on the PUSCHresources.
 4. The method of claim 1, further comprising the WTRUtransmitting a transport block (TB) that was to be transmitted on thePUSCH resources during the transmission opportunity using PUSCHresources associated with a subsequent transmission opportunityassociated with the RRC configured PUSCH resources if the RRC messageindicates that UCI cannot be multiplexed with data on the PUSCHresources.
 5. The method of claim 4, wherein transmitting the TB usingPUSCH resources associated with the subsequent transmission opportunitycomprises transmitting the TB a number of times, the number of timesbeing based on a configured value.
 6. The method of claim 4, wherein thefirst UCI is transmitted on the PUCCH resources before transmitting theTB using PUSCH resources.
 7. The method of claim 4, wherein the firstUCI is transmitted in a first slot; and wherein the TB is transmitted inat least a second slot.
 8. A wireless transmit receive unit (WTRU)comprising: a processor configured at least to: receive a radio resourcecontrol (RRC) message, wherein the RRC message comprises informationindicating physical uplink shared channel (PUSCH) resources for theWTRU, and the RRC message indicates whether or not uplink controlinformation (UCI) can be multiplexed with data on the PUSCH resources;determine to transmit first UCI during a time period that overlaps witha transmission opportunity associated with the PUSCH resources; andtransmit the first UCI, wherein the WTRU multiplexes the first UCI onthe PUSCH resources associated with the transmission opportunity if theRRC message indicates that UCI can be multiplexed with data on the PUSCHresources, and the WTRU transmits the first UCI on one or more physicaluplink control channel (PUCCH) resources if the RRC message indicatesthat UCI cannot be multiplexed with data on the PUSCH resources.
 9. TheWTRU of claim 8, wherein the first UCI comprises hybrid automatic repeatrequest (HARQ)/acknowledgment (ACK) information.
 10. The WTRU of claim8, wherein the processor is further configured to not transmit the firstUCI using the PUSCH resources during the transmission opportunity if theRRC message indicates that UCI cannot be multiplexed with data on thePUSCH resources.
 11. The WTRU of claim 8, wherein the processor isfurther configured to transmit a transport block (TB) that was to betransmitted on the PUSCH resources during the transmission opportunityusing PUSCH resources associated with a subsequent transmissionopportunity associated with the RRC configured PUSCH resources if theRRC message indicates that UCI cannot be multiplexed with data on thePUSCH resources.
 12. The WTRU of claim 11, wherein the processor isfurther configured to transmit the TB using PUSCH resources associatedwith the subsequent transmission opportunity a number of times, thenumber of times being based on a configured value.
 13. The WTRU of claim11, wherein the first UCI is transmitted using PUSCH resources.
 14. TheWTRU of claim 11, wherein the first UCI is transmitted in a first slot;and wherein the TB is transmitted in at least a second slot.
 15. TheWTRU of claim 12, wherein the RRC message further includes theconfigured value.
 16. The WTRU of claim 14, wherein the second slot isan immediately subsequent slot to the first slot.
 17. The method ofclaim 5, wherein the RRC message further includes the configured value.18. The method of claim 7, wherein the second slot is an immediatelysubsequent slot to the first slot.